[TEC] Real navigation Tutorials

[Vlaxie]

Originally Posted by Nathaniel B.

Could you provide the latitude, declination and Ho (altitude) of the Sun? That would help me double check the calculation.


You left out the "cos(LHA)" part of the equation above, so I'm not sure if you took that into account. It means that you must find the arccosine of the result from what you did quote. Another way to write the equation (which might make more sense) is:


acos((sin(Ho) - sin(Dec.) · sin(Lat.)) / (cos(Dec.) · cos(Lat.))) = LHA


Also, one thing I forgot to mention is that, technically, the result you get is not necessarily the LHA proper. It is actually what is sometimes referred to as "t": the "meridian angle" of the Sun (or how many degrees away from the local meridian the Sun is, either east or west). If you took your sight after local noon, t = LHA. If you took your sight before local noon, 360° - t = LHA.


The difference between the LHA and GHA of the Sun is your longitude. If your actual longitude is indeed 19°04' E, then the Sun will be 19°04' farther west at your location. If we add your longitude to the GHA of the Sun, we get: 59°58' + 19°04' = 79°02'. That is what the LHA of the Sun will be at your location. (Hint: when comparing GHA to LHA, add longitude to GHA if east of Greenwich, subtract if west.)



If we take the arccosine of 0.82, we get t = 34.9152... or 34°54.9'. Since you state that you took the sight after local noon, t = LHA. This is clearly way off from the expected value of 79°02'. On the other hand, assuming you did take the arccosine of the result, 0.82° = 0°49.2' ... also way off.


But, again, I would need all of the actual data to begin to track down exactly what went wrong. It could very well be that the sim does not have the Sun at the correct altitude for your location. Multiple people on this forum have come to the conclusion that SH does not correctly model the positions of the heavenly bodies. I do not play SH, so I cannot personally verify this.

Alrighty, I measured again and here are the numbers, these are from the 1st of September 1939, 16:00 GMT (17:00 hrs local)

Ho 21° 34'
dec N 8° 27.4'
lat N 54° 41'


The Sun's GHA at the time of measurement is 59° 58.0 and I know that my actual longitude is around 19° 04' E. I've been wondering about the accuracy of SH5's celestial sphere, but I found that latitude myself and it's pretty accurate to what the ingame navigator calculates so I'm hoping it's good enough for longitude too (also I measured that sun angle in a slightly rough sea so if the result is a bit different than expected that's the reason why)

[Sean C]

Okay, so here's how the calculation should have gone:


acos((sin(21°34') - sin(8°27.4') · sin(54°41')) / (cos(8°27.4') · cos(54°41')))


acos((0.367583568 - 0.147061367 · 0.815969464) / (0.98912737 · 0.578095005))


acos((0.367583568 - 0.119997585) / 0.571809592)


acos(0.247585984 / 0.571809592)


acos(0.432986762) = 64.34274255 or 64°20.6'


If we subtract the GHA of the Sun from the LHA, we get a longitude of 4°22.6' E. This is also clearly wrong. I did check your data for the Sun on the date you gave and it is correct. I'm not sure how you initially got a value of 0.82, though.


Anyway, you wrote that you "measured that sun angle in a slightly rough sea so if the result is a bit different than expected that's the reason why". That's perfectly normal under the conditions. However, if we calculate what the altitude of the Sun should have been at that time and location, we get:


asin(sin(8°27.4) · sin(54°41') + cos(8°27.4) · cos(79°02') · cos(54°41')) = 13°13.5'


That's a difference of 8°20.5' from your measured altitude. This is far too much error for an accurate determination of longitude (or for any navigational purpose). An error of a few tenths of an arcminute would be acceptable. Even a measurement error of one whole arcminute at that latitude would result in an error in longitude of a little more than 1 nautical mile.


(Note also: the farther off your estimated latitude is from your actual latitude, the greater the error in longitude will be. However the closer the Sun is to due East or West when the sight is taken, the smaller this error will be. But I don't think that is the problem here. The azimuth of the Sun at the time of your sight should have been 266° - almost due West.)


In summary: the only problem I can find is in the measured altitude of the Sun. What the cause of this error is, I cannot say.

[Japo32]

Hello

In the first page I cannot see the images. Can someone post them? I don't find a good sextant tutorial anywhere. only this french one, but it is complicated to me:

http://www.mille-sabords.com/forum/i...howtopic=57739

Thanks!

[Sean C]

Originally Posted by Japo32

Hello

I don't find a good sextant tutorial anywhere. only this french one, but it is complicated to me

If you need help understanding how to do celestial navigation in general, I can assist you with that.

[vdr1981]

Here is also a table of corrections for local apparent noon latitude calculations in SH5 world which I have created during my extensive testing.

http://www.mediafire.com/file/5i7853...ions.docx/file

Note that this applies to TWoS only. I still have to learn and test longitude calculations, lat/long determination using stars ect. In general my conclusion is that in SH5 world the "sky" is accurate and follow real world rules but certain corrections have to be applied for highly accurate results... Happy navigating.

[d3vnu11]

After a 10 year break of playing I'm back into the game. Specially during these current times I'm looking for some help. On getting mods up-to-date. I have the steam version and the uplay download version of the game from long ago.
I currently use these mods looking cleanup and update mods any help would greatly be appreciated in consolidating and updating and removing mods that are no longer needed or obsolete.
Best Regards,
d3vnu11


Generic Mod Enabler - v2.6.0.157
[C:\Program Files (x86)\Steam\steamapps\common\Silent Hunter 5\MODS]

Magnum_Opus_v0_0_1
IRAI_0_0_30_ByTheDarkWraith
NewUIs_TDC_6_8_0_ByTheDarkWraith
NewUIs_TDC_6_8_0_Real_Navigation
FX_Update_0_0_19_ByTheDarkWraith
TheDarkWraith_DC_Water_Disturbances_v2_0_SH5
Dynamic Environment SH5 Basemod (realistic version) V2.1
Dynamic Environment SH5 BrighterNights V2.1
Dynamic Environment SH5 Undersea (temperate and polar) V2.1
Dynamic Environment SH5 Waves (realistic version) V2.1
Dynamic Environment SH5 Sounds V2.1
Stormys DBSM SH5 v1.3 Basemod
Stormys DBSM SH5 v1.3 HOTFIX 3
Stormys DBSM SH5 v1.3 optional scary creaks
Stormys DBSM SH5 v1.3 optional remaining orig sounds converted to 22Khz
Stormys DBSM SH5 v1.3 optional NavMap babelling
Stormys DBSM SH5 v1.3 additional crew sounds beta6
Trevally Automated Scripts v0.6
sobers see thru wake fix
sobers smaller water drops
Equipment_Upgrades_Fix_1_2_byTheBeast
stoianm EnvWeather V1 SH5
Manos Scopes-patch for 16x9
Critical hits 1.1 Torpedos
Critical hits v 1.2
EQuaTool 01.01 by AvM - double set - Large plus Flat Style
Church's NavMap v1.0 - Illyustrator's Version
Church's NavMap v1.0 - Red Lines
Speech Recognition_MiTons_NewUI_Editon_v0.4.1_english
Grossdeutscher Rundfunk
AirTorpedoes
TDW_Mines_Subnets_Detectable_in_hydro (OH II v1.4)
OPEN HORIZONS II_full v1.4
OHII v1.4 Patch2 Full
MyKey

[Aktungbby]

d3vnu11!

[d3vnu11]

Originally Posted by d3vnu11

After a 10 year break of playing I'm back into the game. Specially during these current times I'm looking for some help. On getting mods up-to-date. I have the steam version and the uplay download version of the game from long ago.
I currently use these mods looking cleanup and update mods any help would greatly be appreciated in consolidating and updating and removing mods that are no longer needed or obsolete.
Best Regards,
d3vnu11


Generic Mod Enabler - v2.6.0.157
[C:\Program Files (x86)\Steam\steamapps\common\Silent Hunter 5\MODS]

Magnum_Opus_v0_0_1
IRAI_0_0_30_ByTheDarkWraith
NewUIs_TDC_6_8_0_ByTheDarkWraith
NewUIs_TDC_6_8_0_Real_Navigation
FX_Update_0_0_19_ByTheDarkWraith
TheDarkWraith_DC_Water_Disturbances_v2_0_SH5
Dynamic Environment SH5 Basemod (realistic version) V2.1
Dynamic Environment SH5 BrighterNights V2.1
Dynamic Environment SH5 Undersea (temperate and polar) V2.1
Dynamic Environment SH5 Waves (realistic version) V2.1
Dynamic Environment SH5 Sounds V2.1
Stormys DBSM SH5 v1.3 Basemod
Stormys DBSM SH5 v1.3 HOTFIX 3
Stormys DBSM SH5 v1.3 optional scary creaks
Stormys DBSM SH5 v1.3 optional remaining orig sounds converted to 22Khz
Stormys DBSM SH5 v1.3 optional NavMap babelling
Stormys DBSM SH5 v1.3 additional crew sounds beta6
Trevally Automated Scripts v0.6
sobers see thru wake fix
sobers smaller water drops
Equipment_Upgrades_Fix_1_2_byTheBeast
stoianm EnvWeather V1 SH5
Manos Scopes-patch for 16x9
Critical hits 1.1 Torpedos
Critical hits v 1.2
EQuaTool 01.01 by AvM - double set - Large plus Flat Style
Church's NavMap v1.0 - Illyustrator's Version
Church's NavMap v1.0 - Red Lines
Speech Recognition_MiTons_NewUI_Editon_v0.4.1_english
Grossdeutscher Rundfunk
AirTorpedoes
TDW_Mines_Subnets_Detectable_in_hydro (OH II v1.4)
OPEN HORIZONS II_full v1.4
OHII v1.4 Patch2 Full
MyKey

Generic Mod Enabler - v2.6.0.157
[C:\Program Files (x86)\Steam\steamapps\common\Silent Hunter 5\TWoS_Parts]

Never mind I just went for it after backing up the game. TWoS pretty much is the defacto expansion

TWoS Real Navigation
TWoS Neutrals Illuminated Only_Until [Date]
TWoS Campaign Advance Verifier Testing
Speech Recognition_MiTons_NewUI_Editon_v0.4.1_english
TWoS Remove Map Plastic Cover
TWoS SM Interior_Food Stocks
Grossdeutscher Rundfunk
EQuaTool 01.01 by AvM - double set - Large plus Flat Style

all seems well I'm excited because I'm sailing off to help with the Baltic Operation. Big thanks to all the mod devs, and content providers you made this game a historical archive of knowledge.
Best Regards,
--d3v

[vdr1981]

Originally Posted by d3vnu11

Generic Mod Enabler - v2.6.0.157
[C:\Program Files (x86)\Steam\steamapps\common\Silent Hunter 5\TWoS_Parts]

Never mind I just went for it after backing up the game. TWoS pretty much is the defacto expansion

TWoS Real Navigation
TWoS Neutrals Illuminated Only_Until [Date]
TWoS Campaign Advance Verifier Testing
Speech Recognition_MiTons_NewUI_Editon_v0.4.1_english
TWoS Remove Map Plastic Cover
TWoS SM Interior_Food Stocks
Grossdeutscher Rundfunk
EQuaTool 01.01 by AvM - double set - Large plus Flat Style

all seems well I'm excited because I'm sailing off to help with the Baltic Operation. Big thanks to all the mod devs, and content providers you made this game a historical archive of knowledge.
Best Regards,
--d3v

Remove Grossdeutscher Rundfunk, an improved version of this mod is already withing TWoS...

[d3vnu11]

Originally Posted by vdr1981

Remove Grossdeutscher Rundfunk, an improved version of this mod is already withing TWoS...

[Sean C]

Originally Posted by BillyTimmerman

That's perfectly normal under the conditions. However, if we calculate what the altitude of the Sun should have been at that time and location

I'm not sure what you're trying to accomplish by what you're doing, but I'm reporting it as spam as it is not helpful.

[J0hn Shadow]

Hi there,I'm using the TWOS Mega mod, I love it BTW, but I don't know what is going on with Emil atm, but it's clear conditions, 0 m/s wind and so on (turned it on in the TDW Patch Viewer) and he don't give me a fix celestial Position. Anyone knows the Problem? I started a new Campaign and I'm in the Danzig Bay right now.
Maybe somebody who knows the Problem?

[Macgregor the Hammer]

This is really good stuff! It's almost identical to the Coast Guard Auxiliary Celestial Navigation lesson syllabus I studied when I was trying to get my sailing master's license back in the '89's. I think I still have the books somewhere. Thanks for posting!

[MrArt]

Hello!

I am using Real Navigation with TWOS. I started a new campaign. When I used the sextant to calculate the coordinates I saw that the sky was behaving very strangely. If my time zone is GMT +1 then I must use the Nautical Almanac with a GMT -1 time, and if the time zone is GMT -5
then I have to use GMT +5 time (checked this with Stellarium). Only in this case will all the calculations be correct. How to fix it?

And is there a way to increase the sextant zoom level to increase the accuracy of observations?

[Aktungbby]

J0hnShadow! & MrArt!